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Letters Patent No. 79,974, dated July 14, 1868.

IMPROVEMENT IN TOOL-HOLDER.

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To ALL WHOM IT MAY OONOERN:

A Be it known that I, JACOB W. HASKELL, of Boston, in the county of Suffolk, and State of Massachusetts, have invented a. new and improved Holder for such Tools as are employed in Boring; and I do hereby declare that the following is a iullA and exact description of my invention, reference being had to the accompanying drawings. Y

This invention relates to a peculiarly-constructed and arranged device, which is intended to hold short bits or. cutters of proper form, and atthelocation required in boring in lathes.

Figure 1 of the drawings shows my improvedholder in plan, and

Figure 2 shows the same in longitudinal section.

This holder is designed to be used in the rectangular holes found in the posts which are attached to the slides of lathes. The cutting-tool ismarked a, and is of the form shown in the drawing, or in any other form adapted to the purpose.. This tool has a shank, b, by which it is clamped by being encompassedby1 the slotted head c of the clamp-bolt d, which works in the bore of the tube e, and by the nutf on the bolt d, draws and clamps the tool-shank againsttho end of the tube, and holds the tool firmly with' respect to the'tube.' The bolt dis ma'de small enough at the nut-end to admit of the application cfa coiled spring, g, as shown in 5g. 2, which is compressed in the `act of clamping the tool to the tube e, and expands when the nut-f is turned in the reverse direction, and by its expansion separatesthe head c o the bolt d from the tube e.

'lose'curo the device described, which may be termed the boring-arbor, boxes h z' are made to fit upon the tube e, these boxes being of rectangular outline, and of such sizejas willA ill the rectangular hole in the post on' the lathe-slide, so that, when 'the set-screw in said post is brought down upon the upper box, the boring-arbor is firmly clamped in place. To-prevent-tlie tube e from turning in the boxes h, z', when stress is brought upon the tool a, a spline, o, s out in tbe tube, and a feather, n, is fixed in one of the boxes, as shown,\so as lto t'the spline o.

The boringarbor can be set with the cutting-tool projecting as farrfrom the post on the lathe-slide as may berneeded to enable the cutter a to reach the'distunoe required in boring, and the traverse of the tool can be eiected by allowing the lathe-slide to move, or, it desirable, under some circumstances, the screw holding the boxes maybe slackenedslightly, and, by pressure applied at the rear, either against the bolt d or tube e, the

tube e may be advanced through the boxes h a', thus carrying the cutter a to its work. The head c is mortised into the-end o f tube e, as shown at s, in g. 1, to prevent turning of the head c with relation to thetube e. l Il claimthe combination ofthe tube e, bearing vthe mortise-headed bolt d, wth`half boxes t t', when the tube and boxes are-connected with. a. feather and spline, and are otherwise arranged, substantially as `and forthepuri pose set forth.

' JACOBy W. HASKELL.

Witnesses:

'.G'so. L. ROBERTS, i

'W. B.' Gtnnsox.l 

